package com.dh.manager.util;

import com.dh.core.constant.WxConstant;
import io.swagger.annotations.ApiModelProperty;
import org.apache.commons.codec.binary.Base64;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.springframework.stereotype.Component;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import javax.validation.constraints.NotNull;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
import java.security.AlgorithmParameters;
import java.security.Security;
import java.util.Arrays;


public class WxUtils {
    //解决java.security.NoSuchAlgorithmException: Cannot find any provider supporting AES/CBC/PKCS7Padding
    static {
        Security.addProvider(new BouncyCastleProvider());
    }

    /**
     * 解密
     *
     * @param content 目标密文
     * @param key     秘钥
     * @param iv      偏移量
     * @return
     */
    @ApiModelProperty("解密微信小程序的getUserProfile")
    public  static  String decrypt(@NotNull String content, @NotNull String key, @NotNull String iv) {
        String result = "";
        // 被加密的数据
        byte[] dataByte = Base64.decodeBase64(content);
        // 加密秘钥
        byte[] keyByte = Base64.decodeBase64(key);
        // 偏移量
        byte[] ivByte = Base64.decodeBase64(iv);
        try {
            // 如果密钥不足16位，那么就补足. 这个if 中的内容很重要
            int base = 16;
            if (keyByte.length % base != 0) {
                int groups = keyByte.length / base
                        + (keyByte.length % base != 0 ? 1 : 0);
                byte[] temp = new byte[groups * base];
                Arrays.fill(temp, (byte) 0);
                System.arraycopy(keyByte, 0, temp, 0, keyByte.length);
                keyByte = temp;
            }
            if (ivByte.length % base != 0) {
                int groups = ivByte.length / base
                        + (ivByte.length % base != 0 ? 1 : 0);
                byte[] temp = new byte[groups * base];
                Arrays.fill(temp, (byte) 0);
                System.arraycopy(ivByte, 0, temp, 0, ivByte.length);
                ivByte = temp;
            }
            // 初始化
            Security.addProvider(new BouncyCastleProvider());
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding", "BC");
            SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");
            AlgorithmParameters parameters = AlgorithmParameters
                    .getInstance("AES");
            parameters.init(new IvParameterSpec(ivByte));
            cipher.init(Cipher.DECRYPT_MODE, spec, parameters);// 初始化
            byte[] resultByte = cipher.doFinal(dataByte);
            if (null != resultByte && resultByte.length > 0) {
                result = new String(resultByte, "UTF-8");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }

    @ApiModelProperty("获取用户的openid和session_key")
    public static String getOpenId(String code) {
        BufferedReader in = null;
        //appid和secret是开发者分别是小程序ID和小程序密钥，开发者通过微信公众平台-》设置-》开发设置就可以直接获取，
        String url="https://api.weixin.qq.com/sns/jscode2session?appid=" + WxConstant.APP_ID
                +"&secret="+WxConstant.APP_SECRET
                +"&js_code="+code+"&grant_type=authorization_code";
        try{
            URL weChatUrl = new URL(url);
            URLConnection connection = weChatUrl.openConnection();
            connection.setConnectTimeout(5000);
            connection.setReadTimeout(5000);
            connection.connect();
            in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            StringBuffer sb = new StringBuffer();
            String line;
            while ((line = in.readLine()) != null) {
                sb.append(line);
            }
            return sb.toString();
        }catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
    }

}
